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name: prompt-engineer-agent-prompts-evals description: | Guides prompt engineering for tool-using agents—system and developer prompts, tool schemas, handoffs and subagents, golden datasets, offline eval harnesses, regression CI, LLM-as-judge rubrics, and release gates for prompt changes. Use when authoring agent prompts, building eval suites for agents or copilots, debugging tool-selection failures, designing judge rubrics, or gating prompt deploys—not for general few-shot/CoT patterns only (prompt-engineer), full RAG pipelines (ai-engineer), adversarial red-team campaigns (ai-redteam), or AI ops SLOs (ai-lead-ops). For managing prompt/eval teams, release policy, and hiring, use engineering-manager-agent-prompts-evals—not this skill.

Prompt Engineer — Agent Prompts & Evals

When to Use

• Write or refactor system/developer prompts for agents with tools
• Design tool descriptions and parameter schemas the model must choose correctly
• Build golden datasets and scenario suites (multi-turn, failures, edge cases)
• Implement offline eval harnesses and CI regression for prompts
• Define LLM-as-judge rubrics and human calibration samples
• Set release gates when prompts or tool lists change
• Debug wrong tool, looping, or format break in agent traces

When NOT to Use

• General prompt patterns without agent/eval focus → prompt-engineer
• End-to-end RAG indexing, retrieval, serving → ai-engineer
• Jailbreak and abuse red-team engagements → ai-redteam
• Org-wide model rollout and incident ops → ai-lead-ops
• Token cost program across product → ai-token-improvement-plan-engineer
• Vertical squad management and launch PM → engineering-manager-vertical-ai-products
• Prompt/eval team management and governance → engineering-manager-agent-prompts-evals

Related skills

Need	Skill
Broad prompt design and production guardrails	prompt-engineer
RAG, agents in production code	ai-engineer
Launch eval gates (manager view)	engineering-manager-vertical-ai-products
Risk tier and policy	ai-risk-governance
Adversarial testing	ai-redteam

Core Workflows

1. Agent prompt structure

System vs developer messages, tools block, constraints, handoffs.

See references/agent_system_prompts.md.

2. Eval datasets

Golden sets, coverage matrix, synthetic and SME-labeled examples.

See references/eval_dataset_design.md.

3. Harness and metrics

Offline runs, pass/fail, tool accuracy, trajectory checks.

See references/eval_harness_patterns.md.

4. Judges and rubrics

LLM judge design, bias controls, human agreement.

See references/llm_judge_rubrics.md.

5. Versioning and regression

Prompt semver, baselines, CI gates, rollback.

See references/prompt_versioning_regression.md.

6. Scenario catalog

Multi-turn, tool error, refusal, escalation cases.

See references/agent_eval_scenarios.md.

Output standards

• Every eval case has input, expected behavior (not always exact text), tags
• Tool schema changes include eval delta in PR description
• Judge rubrics published with scoring scale and known failure modes
• No production prompt change without baseline comparison on golden set

When to load references

• Prompts → references/agent_system_prompts.md
• Data → references/eval_dataset_design.md
• Harness → references/eval_harness_patterns.md
• Judges → references/llm_judge_rubrics.md
• CI → references/prompt_versioning_regression.md
• Scenarios → references/agent_eval_scenarios.md